In both meat and vegetarian patties, Clear Labs found some additional ingredients that may turn the stomachs of the hardiest eaters, according to “The Hamburger Report,” a molecular study of a beloved American food.

Researchers also pointed out the conspicuous absence of other ingredients — like beans missing from a vegetarian black bean burger.

“This report provides new insights into the burger product industry to give suppliers, manufacturers, and retailers a representative overview of the supply chain at large and provides insights based on an objective molecular analysis into how we can strengthen the good and improve the bad,” the company wrote on its website.

Here are more of the findings:

6% of meat burgers were identified as problematic with substitution, hygienic issues and pathogenic contamination

One sample tested positive for human DNA

Three samples tested positive for rat DNA

46% of samples contained more calories than reported on labels or in menus

49% of samples contained more carbohydrates than reported

6% of vegetarian burgers were identified as problematic with substitution, hygienic issues, and pathogenic contamination